The self-propelled industrial machine works in various field of working sites. Dump truck is an example of the self-propelled industrial machine. The dump truck has a loading platform (vessel) adapted to move up and down on a vehicle body frame, the vessel is adapted to load substances such as crushed stones, earth and sand, etc. Then, the dump truck travels to a collection yard to discharge the loaded objects. Then, the dump truck goes backward and is stopped at a discharging area. After completion of discharge out of the loaded substances, the vessel is returned to the original position and the dump truck is moved forward.
Hydraulic excavator is another type of the self-propelled industrial machine. The hydraulic excavator comprises a vehicular base structure having a crawler-type or a wheel-type travelling means and an upper swiveling structure being rotatably placed on the vehicular base structure. An operation chamber (cab) is mounted on the upper swiveling structure, and a working mechanism is also provided on the upper swiveling structure, the working mechanism being composed of a boom adapted to cause derricking operation to the upper swiveling mechanism, an arm being connected in vertically rotatable manner to distal end of the boom, and a bucket for digging earth and sand.
Although an operator boarded in the cab of the self-propelled industrial machine such as the dump truck or the hydraulic excavator can be attained front view, but dead angle regions are generated on the back side, and left and right side views. Therefore, some directions may hardly be visible with the naked eye of the operator. For the assistance of facilitating recognition for the situation surroundings of the hydraulic excavator to the operator supplementary, plural number of cameras are mounted on the self-propelling industrial machine to take image around there. The images of the cameras are displayed on a monitor mounted in the cab. By so constructing, the operator can recognize to the direction hardly confirm by sight.
According to Patent Document 1, three cameras are provided at the backward and, the left and right sides of the hydraulic excavator to survey around the hydraulic excavator, the images taken from respective cameras are shown on a display as an image combined each other sequentially. Thereby, movement of an objective substance can be recognized directly by an operator. In addition, Patent Document 2 discloses backward view of an construction machine can displayed on a monitor